Rigid Display Shield

ABSTRACT

A protective shield includes a rigid base layer, and an outer cushioning layer from a flexible film material laminated to an outer surface of the base layer. The outer cushioning layer includes two or more layers of flexible film laminated together via an intermediary adhesive. The protective shield also has a mounting adhesive layer applied on the lower surface of the shield. The mounting adhesive allows the shield to be removably mounted to a display surface, such as a touch screen surface for an electronic device. When the shield is properly mounted to the display surface, the outer layer formed from flexible film material faces away from the display surface. The flexible cushioning layer on the outer surface of the shield allows the shield to protect the display surface such that the display surface can withstand higher levels of impacts without breaking or shattering.

RELATED APPLICATIONS

Not applicable

TECHNICAL FIELD

The present disclosure generally relates to protective shields. Morespecifically, the present disclosure relates to rigid shields thatattach to displays to protect and improve the impact resistance of thedisplay surface.

BACKGROUND

Electronic devices such as smart phones and tablets have displaysurfaces that produce and display visual output. For some devices, thedisplay surface provides an operating interface (e.g., a touch screeninterface) whereby a user can operate, control, or otherwise manipulatethe electronic device. Many of these display surfaces are made of glassor other brittle materials that are subject to cracking, shattering, orotherwise breaking, or other forms of damage, for example, when a deviceis impacted or dropped. For some devices, particularly touch screendevices, breaking the display surface might render the entire electronicdevice entirely inoperable. The damage to repair such a display surfacemay be costly, and in some instances may even be irreparable.

Protective shields can be applied to display surfaces to protect displaysurfaces from mild wear and tear. For example, protective shields can beapplied to video displays and/or touch screens to protect those displaysurfaces from scratches, abrasions, spills, stains, and the like. Theseprotective shields can be removably applied so that when the shieldsbecome scratched, soiled, or otherwise impaired, a user can remove theshield and replace it with a new one. In this manner, the displaysurface can generally remain in a relatively high visibility workingcondition despite being subject to wear and tear. However, whileprotective shields provide protection against normal wear and tear, theyare often ineffective in protecting the displays against impacts. Thatis, the protective shields do not reduce the likelihood that thedisplays will break when they encounter a high impact force.

SUMMARY

The present disclosure describes protective shields that attach todisplay surfaces such as video screens, touch screens, and the like. Theprotective shields include a base layer that is at least partly formedfrom a rigid material (e.g. glass). An outer layer formed from aflexible film material, such as polyethylene terephthalate (PET), islaminated to a front surface of the base layer via a bonding adhesive.The outer layer may include two or more layers of flexible filmlaminated together via an intermediary adhesive. The protective shieldalso has a mounting adhesive layer applied on the lower surface of theshield. The mounting adhesive allows the shield to be removably mountedto the display surface.

When the shield is properly mounted to the display surface, the outerlayer formed from flexible film material faces away from the displaysurface. This provides a softer, flexible surface that absorbs ordissipates impact forces that would otherwise contact the displaysurface. This flexible outer layer may serve as a cushion that increasesthe impact resistance of the shield and/or the display surface.Providing this flexible cushioning layer on the outer surface of theshield as opposed to an inner surface (e.g., between the rigid baselayer and the display surface) surprisingly increases the ability of theshield and the display surface to withstand impacts without breaking orshattering.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded top view of an electronic device with an exampleof a protective shield mounted thereon.

FIG. 2 is an exploded view of a protective shield in accordance withexamples described herein.

FIGS. 3 and 4 are cross sectional views of protective shields attachedto a display surface in accordance with examples described herein.

FIG. 5 is a flow diagram of a method for manufacturing protectiveshields in accordance with examples described herein.

FIGS. 6 and 7 are charts demonstrating the results of experimentstesting the impact resistance of display surfaces protected, or notprotected, by various protective shields.

DETAILED DESCRIPTION

The present disclosure describes examples of a removable protectiveshield. The protective shields (also referred to as protectors, or justshields) are configured to attach to, protect, and be removed from adisplay surface. The display surface can be any surface designed todisplay media, in particular, electronic media. The display surfacesprotectable by the described shields can include video display screens(e.g., televisions, monitors, digital picture frames, advertisingdisplays, etc.), touch screens (e.g., interface screens for mobilephones, tablets, mobile computing devices, touch screen monitors, etc.),or other surfaces designed to display information (e.g., watch faces,clocks, mirrors, etc.). In many cases, the display surfaces willcomprise or be made from glass or other brittle material. Such brittlesurfaces are prone to fracture, shatter, or otherwise break uponexposure to impact or other forces. The described protective shields aredesigned to improve the impact resistance of the display surfaces sothat they can withstand higher levels of impact without breaking.

Protective shields can be formed from flexible materials or stiffer,more rigid materials. The flexible shields and the rigid shields eachhave their benefits and their drawbacks. For instance, shields formedfrom flexible materials, such as plastic or PET, are often more durablethan rigid shields from an impact perspective. Because they areflexible, they do not break or shatter upon exposure to impact ortensile forces as easily as some rigid shields. However, flexibleshields may also be more difficult to install and remain installed on adisplay surface. This is because the flexibility of the shield canresult in wrinkling, warping, or bending that can cause edges of theshield to lift off or peel away from the display surface. Moreover,flexible shields may also be more inclined to generate optical artifactswhen employed in perimeter mounting screen protectors. Examples of suchperimeter mounting protectors are described in disclosures of U.S.patent application Ser. No. 12/780,443 (now issued as U.S. Pat. No.9,128,545), and all applications that claim priority thereto, includingU.S. patent application Ser. No. 13/838,311 (now U.S. Pat. No.8,974,620), Ser. No. 14/599,176 (now U.S. Pat. No. 9,104,256), Ser. Nos.13/186,690, 14/642,406, and 14/794,156, each of which are herebyincorporated by reference in their entirety. These perimeter mountingprotectors can lift the central portion of the shield away from the,which can create a cushion of air between the shield and the protectedsurface that can serve to protect the display surface. However, theseperimeter mounting shields can generate optical artifacts, such asNewton rings, moiré interference patterns, chromatic interference, andthe like, when a protective layer contacts or otherwise comes too closeto the touch screen. These optical artifacts are more likely to occurwith flexible shields, which can sag in the center.

Rigid shields, such as shields made from glass or other stiff materialsalso have both benefits and drawbacks. For example, because they arerigid, the shields are typically easier to install, and tend to remaininstalled on a display. This is particularly true for the perimetermounting shields, as the rigid shields are less likely to sag intocontact with or close proximity with the protected display surface.However, rigid shields do not typically improve the impact resistance ofthe protected display surfaces as well as flexible shields. Because theyare inflexible, the rigid shields do not absorb impact forces, whichoften results in a significant portion of impact forces beingtransmitted to the protected display surfaces. These transmitted forcescan cause the display surface to break or damage, even if the rigidprotector itself remains intact.

The present disclosure describes examples of removable rigid protectiveshields that can improve the impact resistance of the protected displaysurface. The described shields therefore provide benefits of a rigidshield (e.g., easy installation, inhibiting formation of Newton rings,etc.), while also providing the improved impact resistance like a moreflexible shield. In some situations, the shields may be designed tocrack or break before the underlying protected screen. That is, a forcethat may otherwise cause an unprotected display surface to break mayinstead cause the protective shield to break in a manner that absorbsand/or dissipates the impact force such that the underlying displaysurface remains intact. In such a situation, the damaged shield can thenbe removed and replaced with a new shield, keeping the protected displaysurface relatively unharmed.

The protective shields described herein also protect the displaysurfaces against wear and tear such as scratches, abrasions, stains, andthe like. In this manner, the shield—not the display surface—will absorbthe wear and tear, keeping the display surface relatively clean andunharmed. Once the shield is damaged enough to inhibit the viewabilityor operability of the display surface, the shield can be removed toexpose a generally clean display surface. A new shield can then bere-installed on the protected surface, if desired.

The described protective shields improve the impact resistance bylaminating or adhering one or more cushioning layers to an outer surfaceof a rigid layer. The cushioning layers are preferably formed fromflexible material (e.g., flexible PET), and can include one or moreflexible film layers laminated together. The rigid layer is preferablyformed from a rigid or stiff material (e.g., glass), which forms a baselayer of the shield giving the shield a stiffness or rigidity.

It was surprisingly discovered that providing these flexible film layerson the outer surface of the shields (i.e., on the side of the shieldopposite that of the protected display surface) improved the impactresistance of the shield and/or the display surface protected by theshield. It was also discovered that providing the flexible cushioninglayer on the outside of the shield demonstrated an increase in theimpact resistance over similar shields that included a flexible filmlayer on an inner side of the shield (i.e., between the rigid layer ofthe shield and the protected display surface).

FIG. 1 shows an exploded view of an electronic device 1 with a displaysurface 10 protected by a protective shield 100 mounted thereon. Morespecifically, the electronic device 1 is a smart phone (e.g., an IPHONE)with a touch operable surface (i.e., a touch screen) that allows a userto operate the electronic device 1 by capacitive touch. However, whileFIG. 1 shows the device 1 as a touch operable smart phone, it should beunderstood that the presently described shields may be used with anydevice that has a brittle or breakable display surface.

The display surface 10 defines an operating area 20 that is surroundedby a border area 25. The operating area 20 represents the central, orprimary viewing area of the display surface 10, and may correspond witha digital screen that changes display based on the operation of theelectronic device. The operating area 20 may be partially or fully touchsensitive, providing a user interface that allows a user to manipulate,control, or otherwise operate the device 1. The operating area 20 may bedisposed adjacent or enclosed within a border area 25.

The border area 25 may be an inactive area that surrounds the operatingarea 20, and may include features such as brand labelling, graphics,speakers, mechanical buttons, LED lights, non-graphical displays, andthe like. In some instances, the border area 25 may include touchsensitive portions (e.g., touch sensitive buttons or icons) that alsoallow operation of the device 1. In some instances, the border 25 mayexhibit all the functionality of the operating area 20. For example, insome instances where the electronic device 1 comprises a full displaythat extends between all edges of the device, the border area 25 maysimply represent an outer area of the fully operating display. In otherexamples, the border area 25 may be inactive, or largely inactive, suchthat the border provides limited or no operable functionality. In someexamples, the display surface 10 may be curved, or non-planar, such thatat least a portion of the border area 25 is on a different plane thanthe operating area 20.

The operating area 20 of the display surface 10 is protected by a shield100, which is disposed over the display surface 10. In someconfigurations (including the examples shown in FIGS. 2 and 3), theshield 100 attaches to the display surface 10 so that the outerperipheral portion 102 of the shield 100 adheres to the border area 25of the display surface 10. In these examples, the attached shield 100may form a space, or an air gap between the central portion 104 of theshield 100 and the display surface 10, as described in the references inthe patent family of U.S. Pat. No. 9,128,545 (hereby incorporated byreference in its entirety). In other examples (including the exampleshown in FIG. 4), the shield 100 may attach to a majority of the displaysurface 10, including the operating area 20, by a full adhesive, or anadhesive applied to all, or substantially all of the underside of theshield 100.

FIG. 2 is an exploded view of a more detailed example of the protectiveshield 100 of FIG. 1. The protective shield 100 has several layers,which can all be laminated together, for example, via adhesives oradhesive layers, to form a single protective shield 100. In someembodiments, the shield 100, and the layers that form the shield 100,are transparent, or at least translucent or partially transparent, sothat a display surface protected by the shield 100 can be seen andreadily observed by a user. However, in some embodiments the shield 100and/or some or all layers of the shield 100 may comprise a tint, color,polarization, coating, privacy screen feature, or other effects thatrender the shield 100 less than entirely transparent, provided that atleast some portion of a display surface protected by the shield 100 isvisible. However, as will be discussed below, some layers (e.g., masklayer 130 or other layers that may not cover the operating area 20 ofthe display surface 10) may be intentionally darkened or opaque, so asto occlude or hide air bubbles and other objects.

The shield 100 has a thickness that can vary depending on the intendedfunction of the shield 100 and the display surface 10 that it isdesigned to protect. The shield 100 is generally thick enough to providestiffness and rigidity to the shield, and to provide the appropriatelevel of protection, but is thin enough to maintain visibility and keepa low profile. In embodiments where the shield 100 is designed toprotect a touch sensitive surface, the thickness of the shield will bethin enough to maintain touch sensitivity of the touch screen throughthe attached shield 100. That is, the shield 100 should not be thickerthan the capacitive reach of the touch screen, in which case the touchsensitivity of the touch screen would be diminished through the shield.For some touch screen devices, the thickness of the shield shouldgenerally not exceed about 1 mm or about 40 mils (1 mil is equivalent to1/1000th of an inch). In some embodiments, the total thickness of theshield may be between about 20 mils (about 0.5 mm) and about 30 mils(about 0.75 mm). In still further embodiments, the total thickness ofthe shield 100 may be between about 25 to about 27 mils, or betweenabout 0.65 to about 0.67 mm. Of course, in other environments and inother situations the shield 100 may be significantly thicker or thinner,depending on the touch sensitivity of the touch screen and otherfactors.

The example shield 100 of FIG. 2 is shown having seven separate layers.It should be appreciated that in some embodiments, the shield mayinclude more or less layers. It should also be appreciated that somelayers, including some adhesive layers that bond the layers of theshield 100 together, are not shown in FIG. 2. The layers of FIG. 2include a base layer 110, a cushioning layer 120 formed by a first 122and second outer layer 124 laminated together, a mask or spacer layer130, an exposed or mounting adhesive layer 140, and two removable linerlayers 150 and 152.

The base layer 110 forms a rigid or stiff layer, and is formed from arigid or stiff material. For example, the base layer 110 can be, or caninclude glass, reinforced glass, tempered glass, toughened glass, orother versions of safety glass to inhibit the glass from splinteringinto large shards when it breaks. Some versions of the base layer 110may be formed from a flex-glass material, which comprises a glass andplastic mixture thereby providing a material that has more flexibilitythan standard glass. In some examples, the base layer 110 can be formedfrom other rigid materials, including rigid plastics.

The base layer 110 is typically thick enough to provide stiffness andrigidity to the shield, but thin enough to avoid generating visibilityor manipulation issues. In some examples, the base layer 110 has athickness between about 7 mils to about 16 mils, or more specificallybetween about 10 mils and about 15 mils (or about 0.25 mm to about 0.38mm). In some examples, the base layer itself may be about 11 mils toabout 12 mils, or about 0.3 mm in thickness.

Attached to the upper, or outer surface 112 of the base layer 110 is anouter cushioning layer 120. The outer cushioning layer 120 can be formedof multiple layers, as shown in FIG. 2. For example, the outercushioning layer 120 can be formed from a lower layer 122 and an outerlayer 124 laminated together via an adhesive layer (not shown in FIG.2). In some examples, the outer cushioning layer 120 may include onlyone layer, or it may include three or more layers laminated together.

The components of the outer cushioning layer 120 are formed fromflexible materials such that the outer cushioning layer 120 itself isflexible. For example, the films forming the cushioning layer maycomprise PET, polycarbonate, acrylic, and the like. The thickness of thelayers can vary depending on the intended application of the shield. Forinstance, the layers 122 and 124 of the cushioning layer 120 may eachhave a thickness of about 3 mils, about 4 mils, about 5 mils, or about0.1 mm, thereby forming a cushioning layer 120 with a total thickness ofbetween about 6 mils to about 10 mils (e.g., about 8 mils), or about 0.2mm. In this manner, the intermediary adhesive layer that laminates thelayers together may have a negligible thickness that does notsignificantly contribute to the overall thickness of the cushioninglayer 120 or the shield 100. However, the adhesive layer can also helpserve as a shock absorber, cushioning layer, or impact dissipating layerthat helps the shield 100 increase the impact resistance of theprotected display surface 10.

The layers of the cushioning layer 120 are bonded or laminated together,and in some instances, may form a permanent laminate. A “permanent”laminate (or permanent bond, or permanent adhesive), as that term isused throughout this application, refers to a lamination bond that isstronger than laminates, bonds, or adhesives that are referred to asremovable. A permanent laminate, as used herein, intends to bond twosurfaces together, and maintain that bond for the operable life of theshield, but such a laminate may not be literally permanent, as heat,chemicals, tools, or the effects of time, may cause a permanent laminateto de-laminate.

In some embodiments, the outer cushioning layer 120 will be virtuallytransparent and/or clear, and despite being comprised of multiplelayers, will have an appearance of a single layer film. In this manner,each of the layers of the outer cushioning layer 120, including the filmlayers 122 and 124, and the intermediary adhesive layer will have arefractive index that is matched, generally within 0.2, which limits theamount of internal reflections within the cushioning layer 120 that arevisible to human eyes.

The cushioning layer 120 may be bonded or laminated to the outer surface112 of the base layer 110 via a bonding adhesive layer. Like theintermediary adhesive layer bonding the layers of the cushioning layer120 together, the bonding adhesive layer laminating the cushioning layer120 to the base layer 110 may also have a negligible thickness, and itmay help serve as a shock absorber, cushioning layer, or impactdissipating layer. The bonding adhesive layer may form a permanentlaminate between the cushioning layer and the base layer.

One or more layers of the cushioning layer 120 may be coated with a hardcoat layer. Ideally, at least the outer-most layer 124 of the cushioninglayer 120 will have a hard coat (if any layers have such a coat, whichmay not be necessary in all embodiments), so that the outer-most surfaceof the protective shield 100 is hardened, thereby improving the scratchand abrasion resistance of the shield. The hard coat layer may providethe outer surface of the cushioning layer with a pencil hardness valueof about 6H. Since the outer cushioning layer 120 may generally besofter than the inner base layer 100, these outer layers may tend toscratch more easily than a basic glass or rigid shield. Accordingly,coating the outer-most layer 124 of the cushioning layer 120 canincrease the scratch resistance, while still offering the benefits of asoft, cushioning outer layer 120 to absorb and dissipate impacts on theprotected display surface 10. In some examples, lower or intermediarylayers of the cushioning layer 120 may also be provided with a hardcoat.

An annular spacer layer 130, or a mask, may be laminated to a lower, orinner surface 112 of the base layer 110. An exposed adhesive, or amounting adhesive layer 140 may also be applied to the inner surface 112of the base layer 110 and/or to the spacer layer 130. In the embodimentshown in FIG. 2, the spacer layer 130 is applied directly to the innersurface 112 of the base layer 110.

The mounting adhesive layer 140 is configured to removably attach theshield 100 to the display surface 10. That is, the adhesive layer 140 isconfigured so that a user may remove the attached shield 100 when itbecomes damaged or soiled, and re-install a new shield on the displaysurface 10. The adhesive layer 140 may be configured so as not to leavesignificant amounts of (or any) residue behind on the surface 10 afterit is removed. That is, the adhesive layer 140 is configured to remainwith the shield 100 when it is removed from the display surface 10. Thespacer 130 and/or the adhesive layer 140 may be opaque or dark to hideor disguise artifacts or objects such as bubbles and dust that may formbetween the shield 100, the adhesive 140, and the display surface 10.

In some examples, the adhesive can be a pressure sensitive adhesive(e.g., an acrylic adhesive). The adhesive may also be a self-wettingadhesive that facilitates pressing out air bubbles that may form afterinstallation between the shield 100, the adhesive 140, and the displaysurface 10. In one example, the adhesive can be made to have a linearpeel force of about 10 to about 20 g/mm (per ASTM D903).

In FIG. 2, the mounting adhesive layer 140 is applied to the spacer 130,and has a shape/configuration that corresponds to that of the spacer130. This shape/configuration is designed to correspond to that of theborder 25 of the display surface. In this manner in FIG. 2, the spacer130 and the adhesive layer 140 have a shape and configuration thatcorresponds to the shape and configuration of a border area 25 of adisplay surface 10. Similarly, the central portion 104 of the shield(see FIG. 1) corresponds to the central or operating area 20 of thedisplay surface 10. Because the central portion 104 of the shield doesnot have adhesive, attaching the protector to the touch screen devicewill not adhere the protector to the central or primary display. Thismay inhibit, mitigate, reduce, prevent, or even eliminate the formationof undesirable optical artifacts such as floating air bubbles, Newtonrings, moiré interference patterns, and chromatic interference, whilestill maintaining touch sensitivity of the touch screen through theattached protector.

Depending on the thickness of the spacer 130 and the adhesive 140, theshield 100 may also form a space, air gap, or air bearing between anattached shield and the display surface in a resting configuration(i.e., in a configuration where the shield is not being pressed). Thatis, the spacer 130 and/or the adhesive layer 140 can be used to providea spacing, an air gap, a planar bearing, or to otherwise lift thecentral portion of the shield 100, in particular the inner surface 112of the base layer 110 of the shield 100 off the display surface 10 thatit attaches to. In some examples, the spacer has a thickness of betweenabout 1to 3 mils, more specifically, about 2 mils, or about 0.05 mm. Thethickness of the adhesive can vary, and in some examples is betweenabout 3 mils and about 5 mils, or about 0.07 mm thick. Accordingly, thecombined spacer is between about 6 mils and 8 mils, or about 0.12 mmthick. It should be noted that in some examples, the spacing may beprovided by only the adhesive layer 140. That is, the adhesive layer 140may be applied directly to the base layer 110 about the outer periphery102 of the shield 100 without an intermediary spacer 130 there between.

FIG. 2 also shows tabbed liner layers 150 and 152 attached to the outerand inner surface of the shield. The thickness of the liner layers canbe between about 1 mil to about 3 mils, or about 0.05 mm. The innerliner layer 152 is used to protect the adhesive layer 140 prior toapplication to a display surface 10. When a user wishes to apply theshield 100, the inner liner layer 152 may be removed to expose a tackyadhesive layer 140, and the shield may then be pressed against thedisplay surface 10. The inner liner layer 152 may include a tab 153 thatfacilitates grasping and removal of the inner liner layer 152. Likewise,the outer surface of the shield 100 may also have a liner layer 150 thatprotects the cushioning layer 120, or the outer layer 124 of thecushioning layer 120 before it is used. Upon installation of the shield100, a user may peel away the outer liner layer 150 by grasping andpulling on the tab 151. It should be noted that not all embodiments ofthe shield 100 need to include the outer liner layer 150, as a hardcoating on the outer surface 124 may be sufficient to protect theshield.

FIG. 3 shows a cross section of a shield 100 attached to a displaysurface 10 of a device 1. The shield 100 of FIG. 3 may be the sameshield of FIG. 1 and/or FIG. 2, although in FIG. 3, intermediaryadhesive layers 121, 123, and 132 are shown, and the liner layers 150and 152 are removed. The shield 100 comprises a base layer 110,comprised of a rigid material. Laminated to the base layer 110 by way ofa bonding adhesive layer 121 is a cushioning layer 120. The adhesivelayer 121 may form a permanent laminate so that the cushioning layer 120does not readily remove from the base layer 100.

The cushioning layer 120 itself comprises an inner, or lower cushioninglayer 122 and a second or outer cushioning layer 124, laminated togetherwith an intermediary adhesive layer 123, which may also form a permanentlaminate. The cushioning layer 120 is arranged so that when the shield100 is installed on a device 1, the softer cushioning layer 120 facesaway from the display surface 10 and/or the device 1, thereby absorbingimpacts and other forces that would otherwise contact the base layer110. Because the layers 122 and 124 of the cushioning layer 120 aregenerally formed from flexible materials, the cushioning layer providesa softer surface that can absorb and dissipate such impacts. Byemploying multiple flexible layers 122, and 124 (and in some embodimentseven further layers could be applied), the cushioning layer 120 alsointroduces added adhesive layers (e.g., layers 121 and 123) that, whilethey may have negligible thickness, still absorb and dissipate impacts.

In some examples not shown, the shield 100 may further includeadditional layers laminated to the outer surface of the shield 120.These additional layers can be peel away or removable layers that can betorn away from the shield when they become scratched or soiled, therebyexposing a clean new layer there beneath.

FIG. 3 shows the spacer 130 and adhesive layers 140 laminated to thelower, or inner surface 111 of the base layer 110 via another adhesivelayer 132. The adhesive layer 132 may have a negligible thickness andform a permanent laminate so that the spacer 130 and adhesive layer 140remain attached to the shield 100 during operation. The thicknesses ofthe layers of FIG. 3 are shown enlarged for demonstrative purposes, andare not drawn to scale.

Depending on the intended use of the shield 100, the combined thicknessof the spacer 130 and the adhesive layer 140 can vary. For example, thecombined thickness of the spacer 130 and the adhesive layer 140 may bethick enough to lift the shield 100 off the display screen (e.g., sothat the inner surface 111 of the base layer 110 does not come intocontact or close proximity with the operating area 20 of the displaysurface 10), and to form an air gap 160 without creating a separation solarge that the touch sensitivity of a touch screen display surface 10 iscompromised or negatively affected. In some examples, it will bedesirable to maintain a separation distance between the shield 100 andthe display surface 10 of at least about 1 mil, or even at least about 3mils (or about 0.8 mm), depending on the shield materials and thedisplay surface, to inhibit or prevent formation of optical interferenceor artifacts. Thus, in one example, the combined thickness of the spacer130 and the adhesive layer 140 can be between about 3 mils and about 7mils, or between about 0.07 mm and about 0.18 mm. In some examples, thecombined thickness can be between about 4 mils and about 6 mils, orabout 0.10 mm, and about 0.12 mm. In still more specific examples, thecombined thickness can be between about 4 mils and about 5 mils, orabout 0.12 mm.

As noted, where the display surface 10 is a touch screen, the shield 100is configured so that the total separation between the outer surface ofthe shield and the display surface 10 is small enough so that the touchscreen maintains touch sensitivity through the shield 100. That is, thecombined thickness of the mounting adhesive layer 140, the spacer 130,the base layer 110, the cushioning layer 120, and all intermediaryadhesive layers and coatings, is small enough that a user can stilloperate the touch screen through the attached shield 100, preferablywithout a noticeable drop-off in touch sensitivity. This maximum totalthickness value will depend at least in part on the touch sensitivity ofthe touch screen itself, but can be, for example about 20 mils, about 40mils, or about 80 mils.

In some examples, the base layer 110 is sufficiently stiff so that thecentral portion of the base layer 110 and/or the shield 100 remainsseparated from the operating area 20 of the display surface 10 in theresting configuration. However, in some instances the shield 100 maystill sag or droop, and come into contact with or close proximity to thedisplay surface, thereby generating optical artifacts or interference.To help maintain spacing and prevent the formation of optical artifacts,the shield 100 may employ other features that help keep the base layer110 of the shield 100 off the display surface 10. For example, theshield 100 may be pre-formed with a curl or convex curvature (e.g.,formed by molding), wherein the convex curvature facilitates maintainingseparation between the base layer 110 and the central portion of thedisplay surface 10 in the resting configuration (i.e., in aconfiguration where the shield is not being pressed, touched, orotherwise manipulated). Shields with such pre-formed curl or curvatureare described in U.S. provisional application No. 62/293,482, which ishereby incorporated by reference in its entirety.

FIGS. 2 and 3 show examples of a shield 100 that create an air gap 160or spacing between the shield 100 and the display surface 10. However,some examples of the presently described shields will not create an airgap, and will not lift the shield 100 or the base layer 110 off thedisplay surface 10. In such examples, the adhesive layer 140 may be afull adhesive that is applied to all, or substantially all of the innersurface 111 of the base layer 110. In such an example, the shield willnot provide an air gap, but will essentially adhere the entire shield,or a majority of the shield to the display surface. In this manner, theshield 100 may not include a spacer 130 or a mask.

FIG. 4 shows a cross sectional view of an example shield 200 thatemploys a full adhesive layer 240 attaching the shield 200 to thedisplay surface 10 of a device. The adhesive layer 240 is generallyapplied to the full inner surface 211 of the base layer 210 of theshield 200. The adhesive layer 240 is applied so that the shield 200 maystill be removed from the display surface 10 without leaving residuefrom the adhesive layer 240 behind. The adhesive layer 240 is configuredto have a tackiness that inhibits edges and corners of the shield 200from lifting or raising, or otherwise from delaminating without anintent to remove the shield 200. The adhesive layer 240 may be apressure sensitive adhesive, and/ or it may be self-wetting so thatbubbles that form between the shield 200 and the display surface 10 canbe pressed out.

Laminated to the outer surface 201 of the base layer 210 via an adhesive221 is a cushioning layer 220, which cushioning layer 220 comprises twoindividual layers 222 and 224 laminated together by adhesive layer 223.In this manner, the cushioning layer 220 of FIG. 4 is similar or thesame as that of cushioning layer 120 of FIGS. 2 and 3. In bothembodiments shown in FIGS. 2 and 3, and in FIG. 4, the cushioning layeris laminated to the outer surface of the shield 200, thereby absorbingand dissipating impacts that contact the shield 200 to improve theimpact resistance of the protected display surface 10. In some examples,all layers of the shield 200, or at least all the non-opaque layers haverefractive indexes matched to within about 0.2 to inhibit internalreflections and provide an appearance of a single layer shield. As withFIG. 3. The thicknesses of the layers of FIG. 4 are shown enlarged fordemonstrative purposes, and are not drawn to scale.

The shields described herein can be manufactured by various methods.FIG. 5 is a flow diagram of one method 500 for manufacturing protectiveshields. The method includes forming 510 a base layer from a rigidmaterial. The rigid material can be, or can include glass or hardplastic. The base layer is preferably transparent, or at least partiallytransparent such that a display surface protected by the shield canstill be read through the shield. The base layer can be the base layerof any of the shields described above, and can take on a variety ofsizes and shapes depending on the intended application for the shield.

The method 500 further includes laminating or attaching 520 a mask orspacer layer to the lower side (or inner side) of the base layer. Thespacer can be laminated to the base layer with an adhesive, and in someexamples can form a permanent laminate. Not all shields will employspacers, and thus step 520 may not be used in all methods ofmanufacture.

An adhesive layer can then be laminated or applied 530 to the lower sideof the shield. The adhesive layer can be applied as a full adhesive tothe entirety of the lower surface of the shield, or it may be applied toonly a portion of the shield. For example, the adhesive layer may beapplied only to the spacer portion of the shield so that the centralportion of the shield does not adhere to a central portion of a displaysurface. In some examples, where no spacer is used, the adhesive may beapplied directly to the inner surface of the base layer and/or shield.In this manner the adhesive may be applied as a full adhesive, or as apartial adhesive application.

A cushioning layer, or outer layer is formed 540 from flexible material.In some examples, forming 540 the cushioning layer can includelaminating two or more layers of flexible film together, and cutting thecushioning layer. In other examples, the cushioning layer may onlyinclude one flexible layer, and the forming 540 may only include cuttingthe cushioning layer from a sheet or roll of film. The outer cushioninglayer may be applied 550 to the outer surface of the base layer via anintermediary adhesive, which can form a permanent adhesive.

In some examples, protective lining layers can be applied 560 to theinner and outer surfaces of the shield. The shield can then be packagedand distributed. In use, a user can remove the shield from a package,remove the lower lining layer to expose the adhesive, align the shieldover the display surface of a device, and apply pressure to the shieldto attach or adhere the shield to the display surface. If desired, theuser may then remove the outer lining layer (if applicable), and operatea device as appropriate. If and when the shield becomes soiled, cracked,shattered, fractured, or otherwise damaged, the user can remove theshield from the display surface and install a new shield.

It should be noted that, while the above description discusses six stepsof the method 500 performed in one order, the method should not belimited to only this particular order. That is, other methods may applyto some or all of the above steps in different orders. Some steps maynot be performed concurrent with other steps, and some steps may not beperformed at all. For example, method 500 is described as first forming540 the cushioning layer before attaching the cushioning layer to theshield. However, in some examples, the cushioning layer could be formedas it is laminated or applied to the shield. For example, laminating 550the outer cushioning layer could include laminating a first cushioninglayer to the base layer, and then laminating a second cushioning layerto the first cushioning layer. Further, it is not necessarilysignificant that the spacer and adhesive layers be applied to the shieldbefore the cushioning layer as shown in FIG. 5. In some examples, thecushioning layer can be formed and applied to the shield before, orconcurrent with the application of the spacer and adhesive layers.

The present disclosure presents examples of shields 100 that protect adisplay surface 10 and improve the impact resistance of that surface.Because the outer cushioning layer 120 is formed from flexible material,the outer surface of the shield provides added impact absorption. Thisouter surface is designed to face away from the display surface 10 thatthe shield 100 protects. Thus, when an object strikes the shield, orwhen other such impact forces are exerted on the display surface, theouter cushioning layer will be the first surface contacted. Because thissurface is flexible, generally softer, and more giving, the outercushioning surface 120 will absorb and/or dissipate impact forces,thereby reducing the impact force transmitted to the display surface 10.It has also been found that, in some examples, the adhesives between thelayers of the outer cushioning layer 120 further assist in absorbing ofimpacts, which allows multi-layered cushioning layers 120 to provideeven greater impact resistance to the display surface 10.

Surprisingly, it was found that shields having a more rigid outer layerwere not as efficient at absorbing and dissipating impacts as theshields with a flexible or softer layer on the outer surface. This wasfound even where a cushioning layer was provided on the inner surface ofthe base layer. That is, where a cushioning layer of flexible film orfilms was applied to the shield between the base layer and the displaysurface, the display surface did not exhibit the same improved impactresistance as when the cushioning layers were applied on the outsidesurface of the shield. Indeed, in some examples, shields with a rigidouter surfaces (with or without a cushioning layer on an inner surface)did not noticeably improve the impact resistance of the display surfaceover an unprotected surface. Summaries of these experiments are depictedin FIGS. 6 and 7.

FIG. 6 is a bar chart depicting the results of a ball drop test on adisplay surface of an electronic device (specifically, on an IPHONE 6PLUS device), which display surface was protected by various differentprotective shields (or not protected at all). The experiment involveddropping a steel ball onto the tested surface from increasing heightlevels until the display surface broke. The steel ball had a ⅞ inchouter diameter, and a weight that was about that of the electronicdevice (about 4.3 ounces). The electronic device was resting on a ¾ inchthick piece of medium-density fiberboard. The experiment involved firstdropping the steel ball onto the surface at a level of 1 foot, andincreasing the drop height 1 foot at a time until the display surfacebroke. The experiment was conducted several times for each displaysurface, and the drop height that resulted in the display surfacebreaking for each surface is displayed in FIG. 6.

FIG. 6 shows the results from 11 different test samples. From left toright across the graph, those test samples and their average breakheight are as follows:

(1) a full adhesive glass shield—average drop height to break surface 2feet;

(2) a glass shield with a 4 mil thick spacer layer between the shieldand the display surface (the “air” in the figure refers to the air gapformed by the spacer and the mounting adhesive)—average drop height tobreak surface of 2.33 feet;

(3) an unprotected display surface—average drop height to break surfaceof 2.6 feet;

(4) a glass shield with a peripheral mounting adhesive (adhesive applieddirectly to the base layer about only the periphery to create an airgap)—average drop height to break surface of 2.67 feet;

(5) a flex glass shield (sold by VERIZON and BELKEN) with an 8 milspacer layer (formed of material sold by XIGMA and RACING OPTICS) and anair gap—average drop height to break surface of 3 feet;

(6) a glass shield with a 4 mil flexible film layer applied to the baselayer, and a peripheral mounting adhesive to form an air gap averagedrop height to break surface of 3 feet;

(7) a flex glass shield with a full adhesive—average drop height tobreak surface of 4 feet;

(8) a 4 mil flexible film shield with a full adhesive—average dropheight to break surface of 4.5 feet;

(9) a glass shield with an 8 mil flexible film layer applied to the baselayer, and a peripheral mounting adhesive to form an air gap—averagedrop height to break surface of 5 feet;

(10) an 9 mil flexible film shield with a peripheral mounting adhesiveto form an air gap—average drop height to break surface of 5.6 feet;

(11) a 14 mil flexible film shield with full adhesive—average dropheight to break surface of 6 feet.

The results of the experiment demonstrate that test samples employingglass provide an increased impact resistance where the shield employs aflexible film layer on the outer surface. For instance, sample 6, whichemploys a 4 mil flexible film layer applied to glass and an air gapdemonstrates a 0.33 foot improvement over a sample 4, which employs asimilar glass shield without a flexible outer layer. More significantly,sample 9, which includes an 8mil flexible outer layer demonstrates a2.33 foot improvement over sample 4.

The experiment also surprisingly discovered that glass shields using aflexible film layer on the outer surface demonstrated significantimprovement over glass shields that employed a flexible film layer onlyon the inner surface of the shield. For example, sample 2, whichemployed a flexible spacer layer between the base glass layer and thedisplay surface did not significantly improve the impact resistance ofthe display surface, particularly when compared to similar shields witha flexible layer on the outer surface of the shield (e.g., samples 6 and9.

FIG. 7 provides another experiment that tests the protective qualitiesof a glass shield that uses an air gap versus a full adhesive. In theexperiment of FIG. 7, the same steel ball was dropped on either a screenof an electronic device (IPHONE 6PLUS), or on a shield alone, untileither the display surface or the shield itself broke. Lone shields wereapplied to a Lexan polycarbonate material. FIG. 7 shows the results fromfive different test samples. From left to right across the graph, thosetest samples and their average break height are as follows:

(1) a screen was protected by a glass shield with a full adhesive (sameas sample 1 from the experiment of FIG. 6)—average drop height to breakthe phone display surface of 2 feet;

(2) a glass shield with full adhesive applied to Lexan—average dropheight to break shield was 3 feet;

(3) an unprotected screen (same as sample 3 from the experiment of FIG.6)—average drop height to break surface of 2.6 feet;

(4) a glass shield applied to a screen with an air gap (same as sample 4from the experiment of FIG. 6)—average drop height to break surface of2.67 feet;

(5) a glass shield with an air gap applied to LEXAN—average drop heightto break surface of 4.13 feet.

The results of the experiment of FIG. 7 show that the surface of ascreen protected by a glass only shield will tend to break before theglass shield itself will break. Accordingly, it was glass shieldswithout a flexible outer layer provide little in the way of improvedimpact resistance to the protected display surfaces.

Specific examples of protective shields will now be described in detail.The specific descriptions may reference the figures and objects of thefigures as examples of components and other features that may correspondto the described elements. It should be noted that these references aremerely exemplary, and should not be considered as limiting.

In one example, a shield (e.g., shield 100) for protecting a displaysurface includes a rigid base layer (e.g., rigid base layer 110). Therigid base layer has a shape that corresponds to the display surface.The base layer is formed from, or comprises glass, and has a thicknessof between about 10 mils and about 15 mils, or more specifically, about0.3 mm. The shield has a first adhesive layer (e.g., a mounting adhesivelayer 140) applied to a lower surface of the shield (e.g., to the innersurface 111 of the base layer 110, and/or to a spacer layer 130). Thefirst adhesive layer is configured to attach (e.g., removably attach)the shield to the display surface. In one version of the exemplaryshield, the first adhesive layer is applied as a full adhesive (e.g.,adhesive layer 240) to the lower surface of the base layer. In anotherversion, the shield has an annular layer (e.g., a spacer 130) thatsurrounds a central portion of the base layer, and the adhesive layer(e.g., adhesive layer 140) is applied only to the annular layer. Instill another version, the adhesive layer is applied directly to thebase layer, but only about an outer perimeter of the base layer, leavingthe central portion of the shield free of a mounting adhesive. Theshield also includes an outer layer (e.g., cushioning layer 120) appliedto an upper surface (e.g., outer surface 112) of the shield. The outerlayer is, or includes a flexible film material, and is laminated to thebase layer via a second adhesive layer. The second adhesive layer formsa permanent laminate between the base layer and the outer layer. Theouter layer is formed from multiple flexible film layers laminatedtogether with an adhesive (e.g., a permanent adhesive). For example, theouter layer may include a lower flexible film layer (e.g., lower layer122) laminated to the base layer via a second adhesive (e.g., adhesivelayer 121) and an upper flexible film layer (e.g., outer layer 124)laminated to the lower flexible film layer via a third adhesive (e.g.,bonding adhesive layer 123). The upper and lower flexible film materialseach have a thickness between about 3 mils and about 5 mils, morespecifically, about 0.1 mm each. The upper flexible film layer has ahard coating. The shield is configured to attach to the display surfacewith the outer layer facing away from the display surface. The outerlayer of the exemplary shield increases the impact resistance of theshield and/or the impact resistance of the display surface that theshield attaches to. That is, a shield with the outer layer (or a displaysurface protected by a shield with the outer layer) may be able towithstand higher impact forces without breaking than it otherwise wouldbe able to without such an outer layer.

In another example, a touch screen electronic device (e.g., device 1) isprotected with a protector (e.g., shield 200). The device includes atouch screen interface (e.g., display surface 10) for operating thetouch screen device. The protector includes a rigid base layer (e.g.,base layer 210) with an upper surface (e.g., outer surface 212) and alower surface (e.g., inner surface 211), and a shape that corresponds tothe shape of the touch screen. The base layer is made from glass, or atleast comprises a glass material (e.g., the base layer is aglass/plastic composite). A mounting adhesive layer (e.g., adhesivelayer 240) applied to the lower surface of the base layer and/or theprotector removably attaches the protector to the touch screen. Theprotector has an outer layer (e.g., cushioning layer 220) laminated tothe upper surface of the base layer via a bonding adhesive layer (e.g.,adhesive layer 221), and the outer layer includes at least two flexiblefilm layers (e.g., layers 222 and 224) laminated together via anintermediary adhesive layer (e.g., adhesive layer 223). The protector isattached to the touch screen surface with the outer layer facing awayfrom the display surface so that a user operating the touch screendevice will contact the outer surface. The touch screen remains touchsensitive even through the mounted protector.

The present disclosure describes preferred embodiments and examples of adisplay surface protector shield. Those skilled in the art willrecognize that a wide variety of modifications, alterations, andcombinations can be made with respect to the above described protectorshields without departing from the scope of the invention as set forthin the claims, and that such modifications, alterations, andcombinations are to be viewed as being within the ambit of the inventiveconcept. In addition, it should also be understood that features of oneembodiment described herein may be combined with features of otherembodiments described herein to provide yet other embodiments asdesired. All references cited in the present disclosure are herebyincorporated by reference in their entirety.

1) A shield for protecting a display surface, the shield comprising: arigid base layer having a shape that corresponds to the display surface;a first adhesive layer applied to a lower surface of the shield, thefirst adhesive configured to removably attach the shield to the displaysurface; and an outer layer applied to an upper surface of the shield,the outer layer comprising a flexible film material; and a secondadhesive layer adhering the outer layer to the base layer; wherein theshield is configured to attach to the display surface with the outerlayer facing away from the display surface. 2) The shield of claim 1,wherein the outer layer of an attached shield increases the impactresistance of the shield. 3) The shield of claim 1, wherein the rigidbase layer is formed from a material that comprises glass. 4) The shieldof claim 1, wherein the outer layer comprises at least two film layerslaminated together via a third adhesive, wherein the at least two filmlayers comprise the flexible film material. 5) The shield of claim 1,wherein the flexible film material comprises PET. 6) The shield of claim1, wherein the outer layer comprises a lower flexible film layerlaminated to the base layer via the second adhesive, and an upperflexible film layer laminated to the lower flexible film layer via athird adhesive, wherein the upper flexible film layer comprises a hardcoating, and wherein the upper and lower flexible film materials have athickness between about 3 mils and about 5 mils. 7) The shield of claim6, wherein the lower flexible film layer is permanently laminated to thebase layer via the second adhesive layer, and the upper flexible filmlayer is permanently laminated to the lower film layer via the thirdadhesive layer. 8) The shield of claim 1, wherein the base layer has athickness of between about 10 mils and about 15 mils. 9) The shield ofclaim 1, wherein the first adhesive layer is applied about an outerperiphery of the shield and surrounds a central portion of the shield sothat the shield is configured to attach to the display surface withoutthe central portion of the shield adhering to a central portion of thedisplay surface. 10) The shield of claim 9, further comprising anannular layer positioned between the first adhesive layer and the baselayer, the annular layer surrounding a central portion of the baselayer. 11) The shield of claim 10, wherein the annular layer and thefirst adhesive layer have a combined thickness sufficient to lift atleast a portion of the base layer off the central portion of the displaysurface. 12) The shield of claim 11, wherein the base layer issufficiently stiff to maintain a minimum separation between the baselayer and the central portion of the display surface in a restingconfiguration, wherein the minimum separation distance is large enoughto inhibit the formation of optical artifacts. 13) The shield of claim12, wherein the shield is pre-formed with a convex curvature, whereinthe convex curvature facilitates maintaining the minimum separationbetween the base layer and the central portion of the display surface inthe resting configuration. 14) The shield of claim 1, wherein the firstadhesive layer is applied to a majority of the lower surface of theshield so that the shield is configured to attach to the display surfacewithout forming a gap there between. 15) The shield of claim 1, whereinthe display surface is a glass surface. 16) The shield of claim 14,wherein the display surface is a touch screen, and wherein the shield isconfigured to attach to the touch screen so that the touch screenmaintains touch sensitivity through the attached shield. 17) A protectorfor a touch screen of an electronic device, the protector comprising: abase layer having an upper surface, a lower surface, and a shape thatcorresponds to the touch screen, the base layer comprising a glassmaterial; a mounting adhesive layer configured to attach the protectorto the touch screen; and an outer layer laminated to the upper surfaceof the base layer, the outer layer comprising at least two flexible filmlayers laminated together, wherein the protector is configured to attachto the touch screen surface with the outer layer facing away from thedisplay surface, wherein the outer layer increases the impact resistanceof the protector, wherein the attached protector increases the impactresistance of the touch screen, and wherein the protector is configuredso that the touch screen maintains touch sensitivity through theattached shield. 18) The protector of claim 17, wherein the outer layercomprises a lower film layer comprising PET permanently laminated to thebase layer via an intermediary adhesive layer, and an upper film layercomprising PET permanently laminated to the lower film layer via acushion adhesive layer, wherein the upper flexible film layer comprisesa hard coating, and wherein the upper and lower flexible film materialshave a thickness between about 3 mils and about 5 mils. 19) Theprotector of claim 17, further comprising an annular layer positionedbetween the base layer and the mounting adhesive layer, the annularlayer surrounding a central portion of the base layer, wherein themounting adhesive layer is applied to the annular layer so that theprotector attaches to the touch screen surface without the centralportion of the protector adhering to a central portion of the displaysurface, and wherein the annular layer and the first adhesive layer havea combined thickness sufficient to lift at least a portion of the baselayer off the central portion of the display surface. 20) A combinationelectronic device and touch screen protector, the combinationcomprising: an electronic device having a touch screen display, thetouch screen display providing an interface for operating the electronicdevice; and a protector mounted to the touch screen display of theelectronic device via a first adhesive layer, the protector having ashape that corresponds to the touch screen display, the protectorcomprising: a base layer formed from glass, the base layer having aninward surface that faces the touch screen display and an outwardsurface that faces away from the touch screen display; and and an outerlayer laminated to the outer surface of the base layer via a secondadhesive layer, the outer layer comprising at least two flexible filmlayers laminated together via a third adhesive layer; wherein the outerlayer is softer than the base layer, and wherein the touch screendisplay maintains touch sensitivity through the mounted protector.